Apparatus and method for food processing equipment microbial intervention and pasteurization

ABSTRACT

An apparatus and method for microbial intervention and pasteurization of food processing equipment. The apparatus comprises a chamber, a steam generator, a controller, a timer, a power source, and a temperature sensor. The temperature sensor, along with the timer, is used to control the exposure of food processing equipment to steam. After a controlled period of steam application, a chilled water source is used to bathe the food processing equipment. The method includes the steps of placing food processing equipment in the chamber, adding steam to the chamber, continuing to add steam until the surface of the food processing equipment is greater than a first preselected temperature, maintaining the surface temperature by the continued application of steam for a period of about 60 seconds or until it is greater than a second preselected temperature, and then bathing the outer surface of the food processing equipment with chilled water for about 60 seconds. The use of this method results in a 5-log reduction in the population of microorganisms and bacteria on the surface of the food and/or equipment.

RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.09/464,031 filed on Dec. 15, 1999, now U.S. Pat. No. 6,153,240.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention generally relates to systems and methods forcleaning food and food processing equipment, and more particularly, to asurface microbial intervention system and method that provide a 5-log(i.e., 100,000 times) reduction in the amount of microbial pathogens onthe surface of food products and other items, such as food processingequipment.

2. History of Related Art

Fruits, vegetables, and other foods are allowed to remain in contactwith soil, insects, and animals during the time of their growth andharvest. Thus, fresh produce, for example, maintains populations of 10⁴and 10⁵ microorganisms/gram when they arrive at the packing house. Suchmicroorganisms include coliform bacteria, including Enterobacter,Klegsiella spp., and Escherichia coli. The bacteria population tends toremain relatively stable, with no significant influence exerted bytemperature, total precipitation, or length of the day during harvest.Such bacteria may become natural contaminants of frozen concentratedfruit juices.

Since improperly handled food products and processing equipment canserve as a vehicle for the transmission of microorganisms to humans, theelimination of such surface bacteria and pathogenic microbes (whichinclude spoilage organisms) has a tremendous value to the food andhealth industries. For example, there is currently a requirement by theFood and Drug Administration and the United States Department ofAgriculture that all juice products include the following warningstatement on package labels after Nov. 5, 1999.

WARNING: This product has not been pasteurized and, therefore, maycontain harmful bacteria that can cause serious illness in children, theelderly, and persons with weakened immune systems.

Thus, there are not only safety hazards afforded by the presence ofthese surface contaminants, but also marketing and legal implications.

Several approaches to reducing the number of bacteria on the surface ofproduce, food products, and food processing equipment have beenattempted. Common chemical sanitizers, such as chlorine treatments, maybe reasonably effective for equipment sanitation, but these chemicalsapparently have little effect on microorganisms. Another approachincludes steaming herbs, spices, and root/tuber vegetables underpressure, or in a vacuum. Chemical gases may be used to create anantiseptic environment. Each of these processes tends to be expensiveand unreliable, fraught with an abundance of complicated equipment whichtends to break down, and produce unpredictable results.

Even when simple steam is applied to provide microbial intervention atthe surface of food products and processing equipment, it is often thecase that expensive and complicated steam generation apparatus is used.Further, the methods of steam production often involve holding timesthat are overly long; such immersion in steam or hot water tends toadversely affect the organoleptic properties of the food products sotreated.

Therefore, what is needed, is an apparatus and method for microbialintervention and pasteurization of food product and food processingequipment surfaces which is inexpensive and mechanically simple.Further, the apparatus and method should produce repeatable, reliableresults. More specifically, the holding time for the food products to besurface pasteurized should be consistently maintained at the minimumlevel necessary to accomplish a 5-log reduction in the amount of surfacebacteria and/or microorganisms present on external surfaces of the foodand processing equipment. A minimum number of steps to implement theprocess of such a method should be required, and preferably, no specialchemicals should be introduced into the microbial intervention process.

SUMMARY OF THE INVENTION

By way of experimentation, it has been determined that the simplestmethod to accomplish microbial intervention at the surface of foodproducts and processing equipment involves the use of steam and chilledwater. An economically viable and mechanically robust apparatus adaptedfor microbial intervention and pasteurization of food product andprocessing equipment surfaces comprises a chamber in fluid communicationwith a steam generator which is in turn connected to a controller andtimer, a produce temperature sensor, and a power source.

A chilled water source is present in the interior portion of thechamber, and is typically located above a suspension element (e.g.,shelf or conveyor belt) which supports the produce or equipment abovethe bottom surface of the chamber interior. The water source provideswater to bathe the produce or equipment at a (temperature from about 2°to about 5° C., if chilled). The source may be located in the interiorportion of the chamber, or at the exterior of the chamber, depending onthe particular process implemented, and the desires of the user. Thewater may include a sanitizing agent, including a suitable food andequipment grade sanitizer, such as chlorine, in quantities of about 50ppm to about 400 ppm.

The steam generator has a steam pipe by which steam is conducted to thechamber. A water inlet valve allows water into the steam generatorinterior. The water inlet valve is in fluid communication with anorifice and a regulating valve, which ensures that the water volumetricflow never exceeds a preselected level.

The invention also includes a method for microbial intervention andpasteurizing the outer surface of foods and food processing equipmentcomprising the steps of placing the food or equipment in the chamber,adding steam to the chamber, sensing the temperature of the outersurface of the food or equipment, and adding steam to the chamber untilthe sensed temperature is about 74° C. Once the temperature reaches 74°C., a 60-second timer is started to ensure that the surface of theproduce or equipment is exposed to steam for at least 60 seconds at therequired temperature. After this period of time, the outer surface ofthe produce or equipment may be bathed with chilled water for about 60seconds. If chilled, the temperature of the water is about 2°-5° C.

The temperature of the food or equipment surfaces may be sensed byplacing a thermocouple on the surface of the food or equipment, or byinserting the thermocouple into the food, and sensing the temperatureapproximately ¼ inch below the food surface. A remote infrared sensorcan also be placed or located to detect the surface temperature of thefood or equipment, and used to control implementation of the method.

The chamber may be structured as a tunnel with openings at either endfor the continuous pasteurization of food on a roller conveyor. In thisembodiment, the steam generator is connected to three steam pipes in thesteam tunnel and one steam pipe underneath the roller conveyor. Thesepipes have multiple outlets in order to surround the food with steamfrom several directions at once. As the food exits the steam tunnel, thefood is sprayed with a chilled water bath from a chilled water sourceoutside the tunnel.

The food processing equipment pasteurization system may be structured asa stainless steel bonnet or cover which is lowered over a piece of foodprocessing equipment such as a meat slicer. The equipment sits on abottom unit which includes a grated floor and drain pans. A steam inletin the hood allows the steam to enter the bonnet. The steam iscontrolled by venting handles which allow excess pressure to escape.Steam flow is directed across the surface of the hood via multipleopenings. The base unit also contains steam pipes with multiple outletsto allow steam to escape from the hood. Drain pans in the bottom unitcollect steam and particles from the equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the structure and operation of thepresent invention may be had by reference to the following detaileddescription taken in conjunction with the accompanying drawings,wherein:

FIG. 1 is a side-cut-away view of the microbial intervention andpasteurization apparatus of the present invention;

FIG. 2 is a schematic block diagram of the steam generator and itsrelated plumbing;

FIG. 3 is a flow chart which illustrates the method of the presentinvention;

FIGS. 4A, 4B, and 4C illustrate perspective, side cut-away, and topcut-away views, respectively, of the pasteurization steam tunnel andconveyor apparatus;

FIG. 5 is a schematic diagram of the pasteurization steam tunnelintegrated with an industry system set-up;

FIG. 6 is a flow chart which illustrates the method of the invention foran industry system set-up utilizing the pasteurization steam tunnel;

FIGS. 7A and 7B illustrate perspective cut-away and side cut-away views,respectively, of the pasteurization apparatus designed as a steamcontainment unit; and

FIG. 8 is an inside view of the bottom of the steam containment unit.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EXEMPLARY EMBODIMENTS

The microbial intervention and surface pasteurization apparatus 10 ofthe present invention can be seen in FIG. 1. The apparatus 10, which isadapted for surface microbial intervention and pasteurization of produceor food processing equipment 90 having an outer surface 95 comprises achamber 20 with an interior portion 25. A source of chilled water 210,such as a water application nozzle 200. may be located at the interiorportion 25, or at the exterior of the chamber 20. The chamber 20includes a suspension element 80, such as a conveyor or shelf, which isadapted to support the produce or food processing equipment 90 above thebottom surface 27 of the chamber 20. This method of suspending the foodor processing equipment 90 prevents contact with fluids 190 that mayhave come to rest at the bottom surface 27 of the chamber 20. Further,if the suspension element 80 is perforated, chilled water 210 and steamcan more easily circulate around the outer surface 95 of the food orprocessing equipment 90, and drain properly onto the bottom surface 27of the chamber 20. These fluids 19 may be drained from the bottomsurface 27 of the chamber 20 by using the chamber drain 170, which iscontrolled by a drain valve 180.

A controller 60 is in electrical communication with several componentsor elements of the apparatus 10. Thus, the controller 60 operates thesteam generator 30, several valves 140, 150, and 180; the conveyor drive110, if necessary; and the chilled water source 200. The controller 60also senses temperature by way of a remote temperature sensor 70, whichmay be a remote infra-red sensor, or a proximate temperature sensor 75which makes use of a thermocouple 100 to measure the temperature of thesurface 95 of the food or processing equipment 90. To sense temperatureusing the remote temperature sensor 70, a port 72, made of glass orother optically transparent material, must be introduced into the wall28 of the chamber 20.

The steam generator 30 is powered by the power source 50, which is alsoin electrical communication with the controller 60 and the timer 160.The controller 60 and timer 160 may be separate, or may form an integralunit.

The steam generator 30 has a steam pipe 40 which is fluid communicationwith the interior portion 25 of the chamber 20. Water is introduced intothe steam generator 30 by the water pipe 120, which includes a waterinlet valve, which is essentially in fluid communication with theinterior portion of the steam generator 30. The steam generator alsoincludes a backflush pipe 130 having a safety valve 150.

Turning now to FIG. 2, the steam generator 30 peripheral plumbingelements can be seen. Prior art steam generators used for food productsoften include inefficient and complex components. The steam generator 30design of the present invention is simple, reliable, and has thecapability to generate steam very quickly. The steam generator 30 makesuse of one or more sets or series of plates, such as the first platepair 240 and the second plate pair 245, connected to a power source 50to generate steam. The addition of each set of plates increases thequantity of steam generated so that even water having poor conductivitycan be used to produce adequate quantities of steam.

During operation, the interior portion 255 of the steam generator 30 isallowed to fill with water. The source of the water is the water pipe120 that makes use of a filter 250 to provide strained water to theregulating valve 260. An orifice of about 0.033 inches diameter isplaced in line with the water inlet pipe 120 to direct the water flowinto the interior 255 of the generator 30, and a water inlet valve 140is used to turn the flow of water on/off.

As the inlet valve 140 is turned on, water is allowed to flow throughthe water pipe 120, the filter 250, the regulating valve 260, and theorifice 270 into the interior portion 255 of the steam generator 30. Thevolume of water entering the generator 30, and thus the volume of steamgenerated, is adjusted by manipulating the regulating valve 260. Thenon-distilled water which enters the interior portion 255 of thegenerator 30 provides a complete electrical circuit between the firstand second plate pairs 240, 245, allowing a current to flow betweenthem. This current flow serves to heat the plates 240, 245, and generatesteam within the generator 30. Since the backflush valve 150 on thebackflush pipe 130 is closed at this time, the steam is driven into thesteam pipe 40 and enters the chamber 20.

The steam generated is a low pressure steam that eliminates manypotential problems associated with boiler-generated steam. As watermoves across the heated plates 240, 245, dissolved solids such ascalcium, minerals, and salts are deposited in the flowing water. Thewater flow serves to remove the dissolved solids from the electrodes andprevents accumulation. When there is no more need for steam generation,the inlet valve 140 can be closed and the backflush valve 150 opened sothat the water, including deposits, can drain through the backflush pipewith pressure created by an orifice installed in the steam line andbackflush valve 150 into the drain 290.

Turning now to FIG. 3, and reviewing FIG. 1, one possible embodiment themethod of the present invention can be visualized. The method begins atstep 300 by placing food processing equipment or produce in the chamberat step 305 and adding steam to the chamber at step 310. The measuredtemperature of the food or processing equipment outer surface is sensedat step 320 and a comparison is made as to whether the surfacetemperature is greater than some first preselected temperature,preferably about 74° C. as shown at step 330. If not, temperaturemeasurements continue to be made and more steam is added until thesurface temperature of the food or processing equipment is determined tobe greater than or equal to the first preselected temperature, which maybe about 74° C.

After reaching the first preselected surface temperature, a timer isstarted. The timer has a time-out period of about 60 seconds, and steamis added to the chamber on a continuous basis until the end of the60-second time period. This is illustrated in steps 335, 340 and 350.Steps 337 and 338 are optional, and the method may proceed directly fromstep 335 to step 340.

After the surface temperature of the food or processing equipment hasreached the proper temperature, and is maintained at that preselectedtemperature for a period of approximately 60 seconds, steam is no longeradded to the chamber, as shown in step 360, and the outer surface of theprocessing equipment or food is bathed with chilled water for about 60seconds in step 370. This step, which includes bathing the food orprocessing equipment with water (if chilled, at a temperature of fromabout 2° C.) to about 5° C., serves to stop the “cooking” effect of thesteam (or cools the equipment) and shocks organisms on the surface ofthe food or equipment to further reduce their numbers. Testing verifiesthat this method consistently produces a 5-log reduction in thepopulation of microorganisms and bacteria on the surface of food. Themethod ends at step 380. Alternatively, the water may or may not bechilled, and may include chlorine, or some other suitable food andequipment grade sanitizing agent, in quantities of from about 50 ppm toabout 400 ppm.

As shown in FIG. 1, the temperature of the food or equipment 90 can bemeasured in several different ways. One alternative includes the use ofa proximate temperature sensor 75 which is connected to a thermocouple100 by an electronic temperature signal 230. The thermocouple 100 may beplaced on the surface of the food or equipment 90, or located so as tosense the temperature of the food about ¼ inch below the outer surface.Thus, the temperature may be measured on to the outer surface of food orequipment, or at some short distance beneath the outer surface of food.

Another measurement alternative includes the use of a remote temperaturesensor 70 operating through a port 72 to obtain an infra-red temperaturesignal 220 from the surface of the food or equipment 90. The signalsfrom the remote temperature sensor 70, or the proximate temperaturesensor 75 are recorded by the controller 60 and used to operate thesteam generator 30 and timer 160. Non-contact methods of temperaturemeasurement are preferred, since the possible transfer of organismsbetween food products using contact methods is obviated. If thesuspension element 80 is a conveyor, then food or equipment 90 may betransported into, and out of, the chamber 20 using a conveyor drive 110.Otherwise, a door 97 may be used for direct access to the interiorportion 25 of the chamber 20. As noted above, the source of chilledwater 200, shown in FIG. 1 as a water application nozzle 200, may belocated in the interior portion 25 of the chamber 20, or at the exteriorof the chamber 20.

It should be noted that, while some prior art methods describe theapplication of steam to food products, there is no capability providedto prevent excessive heating of the food. It has been determined throughexperimentation that the application of steam which produces surfacetemperatures above about 84° C. significantly affects the organolepticproperties of food products, and derivatives, such as juice. The instantinvention, which includes the capability to measure the surface (orsub-surface) temperature of food may include additional steps to enhancethe repeatability of microbial intervention and pasteurization results.For example, the method may include the steps of sensing the surfacetemperature of the food (or equipment, if desired) 90 so that, iftemperatures greater than a second preselected temperature, for example,greater than about 84° C. are detected, the steam generator 30 will beshut down so as to prevent further increases in surface temperature.This may occur prior to the end of the 60-second time period for steamapplication shown in FIG. 3, at steps 337 and 338. Further, differentfood products may require different preselected temperatures forefficient microbial intervention and pasteurization, and the preventionof adverse effects to organoleptic properties. Thus, the method mayinclude adjusting the surface temperatures from about 74° C. to other,preselected temperatures. The method may also include the steps ofplacing the food or equipment 90 on a conveyor 80 as step 302, operatingthe conveyor drive to introduce the food/equipment 90 into the interiorportion 25 of the chamber 20 at step 303, and continuing with the methodillustrated in FIG. 3, at step 310.

The pasteurization steam tunnel and conveyor apparatus can be seen inFIG. 4. The apparatus 400 comprises a tunnel structure 420 having anouter surface 425, an inner surface 430, an anterior surface 435 and aposterior surface 440. The apparatus also includes a roller conveyor 450which propels food 90 through the tunnel 420. The tunnel 420 containsmultiple pipes 460 which extend the length of the tunnel 420 fromanterior surface 435 to posterior surface 440. Each pipe 460 containsmultiple openings 465 for the introduction of steam through the innersurface 430 of the tunnel 420 to the food 90 on the conveyor belt 450.An additional pipe 460 runs beneath the roller conveyor 450. The pipe460 contains multiple openings 465 for the introduction of steam throughthe openings in the roller conveyor 450. The steam drains onto thebottom surface of the tank drain 470 located underneath the conveyorbelt 450 wherein the water collects to drain through the tank drainpipework 475.

Turning now to FIG. 5, the schematic diagram of the pasteurization steamtunnel 400 integrated with an industry system set-up can be seen. Thisindustry design allows the pasteurization steam tunnel 400 to beintegrated into an efficient food processing system 500 wherebypasteurized foods are routed via additional conveyor belts into bags orboxes and onto pallets for transfer and delivery. The food 90 is loadedonto a roller conveyor 512 and transported to the in-feed table 515.Next, the food 90 is introduced into the pasteurization steam tunnel 400(typically by means of another conveyor 510). After the food 90 isrolled out of the steam tunnel 400 and continues to the box loading ramp520. The boxes 525 are taped at the taping station 530. The food 90 isloaded into the boxes 525, it continues via conveyor 535 to the scale540 for weighing. The boxes 525 then continue via conveyor 545 to theroller conveyor 547 for transfer to one or more pallets 550.Alternatively, the food 90 is rolled out of the steam tunnel 400 andcontinues on the conveyor 555 to the accumulation turn table 560 whereit is placed in bags 565 by the bagger 570. The bags 565 are transportedon the roller conveyor 575 to one or more pallets 580 for transfer anddelivery.

Thus, as shown in FIG. 6, the method of the invention may also includethe steps of placing the food 90 on conveyor 510 in step 302A, operatingthe conveyor drive to move the food onto roller conveyor 512 at step302B, moving the food 90 to the in-feed table 515 at step 302C,introducing the food 90 into the pasteurization steam tunnel 400 at step303, and continuing with the method steps described in FIG. 3 (steps310-370). In this embodiment, the method continues after step 370,wherein the food 90 is chilled/shocked, with steps 379A, 379B, or 379Cwhereby the food 90 proceeds via conveyor to either the boxes 525 instep 379A, the bagger 570 in step 379B, or the scales 540 in step 379C.Further processing may then occur in step 381.

Turning to FIGS. 7A and 7B, the food equipment surface pasteurizationsystem is illustrated as a steam containment unit or chamber 600. Theapparatus includes a stainless steel bonnet or cover unit 610 and abottom or base unit 675. The bonnet 610 has an outer surface 615 and aninner surface 620. The bonnet has one or more steam inlets 625 locatedin the top wall 630 of the bonnet 610. Steam enters the bonnet 610through the steam inlets 625 by a pipe 635. The pipe 635 is bifurcatedinto two smaller pipes 640 and 645 to allow the steam to flow to bothsides of the interior 650 of the bonnet 610. Directional steam flowdevices 655 and 660 extend from the pipes 640 and 645 to introduce steaminto all areas of the bonnet interior 650. Two venting handles 665 and670 are located in the top wall 630 of the bonnet 610 to facilitateregulation of the steam pressure.

The bottom or base unit 675 can be seen in greater detail in FIG. 8. Thebottom floor 680 of the base unit 675 slopes downwardly toward to drainpans 685 and 690. Suspended grates 695 extend across the bottom floor680 in order to support food or food equipment. Steam outlet pipes 700are located along the bottom floor 680 under the grates 695. Multipleoutlets 710 are placed along the steam outlet pipes 700 in order toallow steam to escape into the interior 650 of the bonnet 610 at variouspositions.

Many variations and modifications may be made to the disclosedembodiments of the invention without departing from the spirit andprinciples described herein. All such modifications and variations areintended to be included within the scope of the present invention, asdefined by the following claims.

What we claim is:
 1. An apparatus for microbial intervention andpasteurization of food processing equipment having an outer surface,comprising: a chamber having an interior portion, a bottom surface, anda suspension element for supporting the food processing equipment abovethe bottom surface; a steam generator having a steam pipe, an interiorportion, and a water inlet valve, the steam pipe being in fluidcommunication with the interior portion of the chamber and the interiorportion of the steam generator, and the water inlet valve being in fluidcommunication with the interior portion of the steam generator; achilled water source; a controller in electrical communication with thewater inlet valve and the chilled water source; a timer in electricalcommunication with the controller; a power source in electricalcommunication with the steam generator, the controller, and the timer;and a temperature sensor for sensing the temperature of the outersurface, the sensor being in electrical communication with thecontroller.
 2. The apparatus of claim 1, wherein the chamber includes adrain.
 3. The apparatus of claim 1, wherein the chilled water sourceincludes chilled water maintained at a temperature of from about 2° C.to about 5° C.
 4. The apparatus of claim 1, wherein the steam generatorincludes a backflush pipe having a safety valve.
 5. The apparatus ofclaim 1, wherein the suspension element is a shelf.
 6. The apparatus ofclaim 5, wherein the shelf is a porous shelf.
 7. The apparatus of claim1, wherein the suspension element is a conveyor.
 8. The apparatus ofclaim 7, wherein the chamber includes a drain, and the drain is locatedbeneath the conveyor.
 9. The apparatus of claim 7, wherein the conveyoris a porous conveyor.
 10. The apparatus of claim 1, wherein thecontroller and the timer form an integral unit.
 11. The apparatus ofclaim 1, wherein the temperature sensor is a thermocouple.
 12. Theapparatus of claim 1, wherein the temperature sensor is a remoteinfra-red sensor.
 13. The apparatus of claim 1, wherein the chilledwater source is located in the interior portion of the chamber.
 14. Theapparatus of claim 1, wherein the chilled water source is not located inthe interior portion of the chamber.
 15. The apparatus of claim 1,wherein the steam generator includes a first set of plates and a secondset of plates in electronic communication with the power source.
 16. Theapparatus of claim 1, wherein the water inlet valve is in fluidcommunication with an orifice.
 17. The apparatus of claim 1, wherein thesuspension element is a grated floor.
 18. The apparatus of claim 1,wherein the chamber includes at least one drain pan.
 19. The apparatusof claim 1, wherein the chamber includes a bonnet and a base unit. 20.The apparatus of claim 19, wherein the bonnet has a steam inlet and atleast one venting handle for regulation of steam pressure within thebonnet.
 21. The apparatus of claim 19, wherein the base unit has abottom and includes steam outlet pipes located along the bottom.
 22. Amethod for microbial intervention and pasteurizing a food processingequipment having an outer surface comprising the steps of: placing thefood processing equipment in a chamber; adding steam to the chamber;sensing a measured temperature of the outer surface; adding steam to thechamber if the measured temperature of the outer surface is less thanabout 74° C., otherwise; starting a timer having a timeout period ofabout 60 seconds; adding steam to the chamber until the timeout periodoccurs; stopping the addition of steam to the chamber.
 23. The method ofclaim 22, including the step of bathing the outer surface with waterincluding a sanitizing agent.
 24. The method of claim 22, wherein thestep of sensing a measured temperature of the outer surface isaccomplished using a thermocouple placed in proximity to the outersurface.
 25. The method of claim 22, wherein the step of sensing ameasured temperature of the outer surface is accomplished using a remoteinfra-red sensor.
 26. A method for microbial intervention andpasteurizing a food processing equipment having an outer surfacecomprising the steps of: placing the food processing equipment in achamber; adding steam to the chamber; sensing a measured temperature ofthe outer surface; adding steam to the chamber until the measuredtemperature of the outer surface is greater than a first preselectedtemperature; starting a timer having a timeout period of about 60seconds; adding steam to the chamber until the timeout period occurs, orthe measured temperature of the outer surface becomes greater than asecond preselected temperature, whichever occurs first; and bathing theouter surface with water for about 60 seconds after the timer reachesthe timeout period.
 27. The method of claim 26, wherein the waterincludes a sanitizing agent.
 28. The method of claim 26, wherein thesanitizing agent is a food and equipment grade sanitizer.
 29. The methodof claim 26, wherein the step of sensing a measured temperature of theouter surface is accomplished using a thermocouple placed in proximityto the outer surface.
 30. The method of claim 26, wherein the step ofsensing a measured temperature of the outer surface is accomplishedusing a remote infra-red sensor.
 31. The method of claim 26, wherein thefirst preselected temperature is about 74° C.
 32. The method of claim26, wherein the second preselected temperature is about 84° C.
 33. Amethod for microbial intervention and pasteurizing a food processingequipment having an outer surface comprising the steps of: adding steamto a steam tunnel; sensing a measured temperature of the outer surface;adding steam to the steam tunnel until the measured temperature of theouter surface is greater than a first preselected temperature; startinga timer having a timeout period of about 60 seconds; adding steam to thesteam tunnel until the timeout period occurs, or the measuredtemperature of the outer surface becomes greater than a secondpreselected temperature, whichever occurs first.
 34. The method of claim33, including the step of placing the processing equipment on a rollerconveyor within the steam tunnel.